通过上述代码,我们首先创建了一个名为users的用户表并插入了一些示例数据。随后,我们使用了UPDATE语句批量更新了用户的邮箱。这个过程不仅清晰而且有效,展示了 SQL 在处理大数据量时的强大功能。 在上述代码中,以下几个关键函数或语法十分重要: UPDATE: 用于更新表中的现有数据。 SET: 定义需要更新的列及新值。 CASE...
http://www.ludou.org/update-multiple-rows-with-different-values-and-a-single-sql-query.html
-- update multiple values in the given rowUPDATECustomersSETfirst_name ='Johnny', last_name ='Depp'WHEREcustomer_id =1; Run Code Here, the SQL command changes the value of thefirst_namecolumn toJohnnyandlast_nametoDeppifcustomer_idis equal to1. Update Multiple Rows We use theUPDATEstatement...
Use the @@ROWCOUNT function to return the number of inserted rows to the client application. For more information, see @@ROWCOUNT (Transact-SQL).Variable names can be used in UPDATE statements to show the old and new values affected, but this should be used only when the UPDATE statement ...
In this example, we expand to update multiple columns, setting the values to those from a joined table. --4) Update Multiple columns from a QueryUPDATE[dbo].[MySalesPerson]SET[TerritoryID]=s.[TerritoryID],[SalesQuota]=s.[SalesQuota],[Bonus]=s.[Bonus],[CommissionPct]=s.[CommissionPct]...
VALUES (), (), () 4-Inserting Hierarchical Rows 插入分层行 5-Creating a Copy of a Table 创建表复制 / CREATE TABLE … AS 6-Updating a Single Row 更新单行 / UPDATE … SET … WHERE … 7-Updating Multiple Rows 更新多行 8-Using Subqueries in Updates 在Updates中用子查询 9-Deleting Rows...
UPDATE Multiple Columns SUPPLIER Id CompanyName ContactName City Country Phone Fax Problem: Supplier Norske Meierier (Id = 15) has moved. Change their city, phone, and fax with updated values. UPDATE Supplier SET City = 'Oslo', Phone = '(0)1-953530', Fax = '(0)1-953555' WHERE Id...
Use the @@ROWCOUNT function to return the number of inserted rows to the client application. For more information, see @@ROWCOUNT (Transact-SQL).Variable names can be used in UPDATE statements to show the old and new values affected, but this should be used only when the UPDATE statement ...
https://stackoverflow.com/questions/18797608/update-multiple-rows-in-same-query-using-postgresql 问题描述: SQL update fields of one table from fields of another one I have two tables: A [ID, column1, column2, column3] B [ID, column1, column2, column3, column4] A will always be ...
INSERT 语句激发 DML 触发器,新行在触发器执行期间加载到 插入的 表中。 UPDATE 语句读取该行的 LineTotal 列值,并将该值与 SubTotal 表的PurchaseOrderHeader 列中的现有值相加。 WHERE 子句确保 PurchaseOrderDetail 表中的更新行与 PurchaseOrderID 插入的 表中 行相匹配。